This paper discusses Spanish possessive formation processes within a Distributed Morphology framework. I claim Spanish possessives consist of several morphemes forming an extended syntactic domain; they project from a contentless root taking a pronoun as its complement and are categorized as adjectives. Word formation being subject to general syntactic rules, cyclic Vocabulary Insertion is licensed at word-internal level in their domain, always regulated by a categorizing phasal head. Arguments are provided showing that post-syntactic conditions for root suppletion determine their eventual shape.